1. Field of the Invention:
The present invention relates to a vehicular sound effect generating apparatus for generating a sound effect depending on the rotational speed of the engine on a motor vehicle in the passenger compartment of the motor vehicle.
2. Description of the Related Art:
Heretofore, there have been proposed in the art sound effect producing apparatus for detecting an accelerating or decelerating action made by the driver of a motor vehicle, and producing and radiating a sound effect depending on the acceleration or deceleration through a speaker installed in a motor vehicle cabin into the vehicle cabin, as disclosed in Japanese Laid-Open Patent Publication No. 54-8027 and Japanese Laid-Open Patent Publication No. 4-504916 (PCT Application).
According to the disclosed sound effect producing apparatus, for example, when the rotational speed of the engine mounted on the motor vehicle increases in response to an accelerating action made by the driver, a sound effect having a high frequency and a large sound level is generated depending on the increase in the engine rotational speed and radiated from the speaker into the vehicle cabin to create a staged sound atmosphere in the vehicle cabin.
It is known in the art that a motor vehicle having a manual transmission with stepwise gear ratios and a motor vehicle having an automatic transmission with stepwise gear ratios, even if the motor vehicles are of the same type, have different time-dependent changes in the engine rotational speed for full throttle opening, i.e., different rotational frequency changes [Hz/sec], at each of gear ratios for first, second, third, and fourth gear positions. It is also known in the art that a motor vehicle powered by an engine with a manual transmission and a motor vehicle powered by an engine of the same type with an automatic transmission have different rotational frequency changes in the same gear position.
For example, on a motor vehicle powered by a six-cylinder engine with a manual transmission (MT motor vehicle) shown in FIG. 8 of the accompanying drawings, the rotational frequency change is 31 [Hz/sec] in the first gear position, 16 [Hz/sec] in the second gear position, 7 [Hz/sec] in the third gear position, and 3.7 [Hz/sec] in the fourth gear position. On a motor vehicle powered by a six-cylinder engine with an automatic transmission (AT motor vehicle) shown in FIG. 9 of the accompanying drawings, the rotational frequency change is 19 [Hz/sec] in the first gear position, 7.7 [Hz/sec] in the second gear position, 2.9 [Hz/sec] in the third gear position, and 0.83 [Hz/sec] in the fourth gear position.
However, the above conventional sound effect generating apparatus for generating a sound effect for vehicles fail to disclose or teach anything about the generation of a sound effect in relation to a manual transmission or an automatic transmission.